Detection Rates of TT Virus DNA in Serum of Umbilical Cord Blood, Breast Milk and Saliva

Abstract

To date, the routes of mother-to-infant transmission of TT virus (TTV) have not been fully elucidated. The present study examines the detection rates of TTV DNA in the serum of pregnant Japanese women and in cord blood at the time of delivery, as well as in the saliva and breast milk of mothers one-month postpartum. Primers derived from the well-known translated region N22 (N22 system), as well as the untranslated region (UTR system) were used. The prevalence of TTV DNA in the serum of pregnant women was found to be 11.9% (19/160) using the N22 system and 72.4% (55/76) using the UTR system. No TTV DNA was detected in the cord blood samples (0/160) when the N22 system was used for detection but TTV DNA was detected in 11.8% (7/76) of samples studied with the UTR system. Using the N22 system, TTV DNA was not detected in breast milk, but was detected in saliva. However using the UTR system, TTV DNA was detected in both specimens. These results imply that some babies are vertically infected with TTV via cord blood at the time of delivery or via breast milk or saliva. However, further research is necessary to confirm this hypothesis. polymerase chain reaction; pregnant women; horizontal route of transmission

In Vivo and In Vitro Intragenomic Rearrangement of TT Viruses

“…The presence of TT virus in cord blood has been described previously (11,12,26,47,61), whereas another study failed to confirm these results (34). In only a few cases can the corresponding TT virus type be detected in both mother and child immediately after birth; the majority of children acquire TT virus types other than those demonstrated to be present in their mothers (6,34,51).…”

“…Previous data on the prevalence of TT virus infections in blood samples from lymphoma and leukemia patients have been contradictory (5,10,48), and transplacental infection with TT virus has been described previously (12,26,31,45). The highly conserved region (170 bp; amplicon from nested amplification, 135 bp) of the TT virus control region (36) was amplified in order to cover as broad a spectrum of TT virus types as possible.…”

“…All RNA samples were treated with DNase I (New England Biolabs) to remove any residual DNA, followed by acid phenol (pH 4.8)-chloroform extraction and precipitation with ethanol. One microgram of RNA was reverse transcribed at 42°C for 1 h using 4 U of OmniScript reverse transcriptase from the OmniScript reverse transcription kit and 1 M oligo(dT) [12][13][14][15][16][17][18] primer according to the protocol of the manufacturer (QIAGEN). A second method for cDNA synthesis aimed at preventing secondary structure formation in RNA was performed for 1 h at 65°C using 15 U of ThermoScript reverse transcriptase (Invitrogen) and 1 M oligo(dT) 22 primer.…”

Virus target cell conditioning model to explain some epidemiologic characteristics of childhood leukemias and lymphomas

“…Transplacental or perinatal infection results in virus persistence, as observed in previous studies for established TT virus genotypes. [58][59][60] The expansion of susceptible cells in the course of a newborn child's development, as well as acquisition of new infections with additional TTV types during the first year of life, 49 should result in an increasing number of persistently infected cells and correspondingly to a steadily increasing viral load. It has recently been reported that TT virus concentrations increase with age.…”

Aspectos patológicos, imunológicos e propriedades moleculares do TT vírus

“…Seu foco principal é a transmissão parenteral, através de transfusão sangüínea (16,29) ou por hemoderivados (2,1) . Entretanto alguns estudos têm demonstrado casos de transmissão por via fecal-oral (32) , contato sexual ou transmissão mãe/filho durante a gestação (9,40,17) . O TTV é altamente heterogêneo, em contraste com a maioria dos vírus DNA.…”